Loose-leaf book and leaf therefor



G. H. POTWIN.

LOOSE LEAF BOOK AND LEAF THEREFOR. APPLICATION HLED1UNE4, 1919.

1 ,358,986. V Patented Nov. 16, 1920.

J o 1 9 a T I M .fizflfifo/x W W @5 GEORGE H. POTWIN, OF CHICAGO, ILLINOIS.

LOOSE-LEAF BOOK AND LEAF THEREFOR.

Specification of Letters Patent.

Patented Nov. 16, 1920.

Application filed June 4, 1919. Serial No. 301,663.

T 0 all whom it may concern:

Be it known that I, GEORGE H. Po'rwIN, a citizen of the United States, residing at Ch1cago, county of Cook, State of Illinois, have invented a certain new and useful Improvement in LooseLeaf Books and Leaves Therefor, and declare the following to be a full, clear, and exact description of the same, such as will enable others skilled in the art to which it pertains to make and use the same, reference being had to the accompanying drawings, which form a part of this specification.

In loose-leaf ledgers it has always heretofore been necessary to make some of the openings in the leaves through which the fastening posts pass in such a manner that they will be completely surrounded by the material of the leaves in order to prevent the withdrawal of a leaf in a direction of its plane; since it has been impracticable to make the clamping or holding devices powerful enough to hold a group of ordinary leaves against accidental dislodgment under working conditions. In other words, while it has been common to form leaves with slots opening out through the rear edges, it has been necessary also to provide each leaf with one or more round holes placed at some distance from the edge; and, in placing a leaf in a book or ledger, it has been necessary accurately to aline the round hole or holes with the corresponding hole or holes in the other leaves in order to permit the insertion of a fastening pin.

The object of the present invention is to provide means whereby a leaf may be firmly held in a loose-leaf book without employing holes or openings except, if desired, slots opening directly through the rear edge.

The various features of novelty whereby my invention is characterized will hereinafter be pointed out with particularity in the claims; but, for a full understanding of my invention and of its objects and advantages, reference may be had to the following detailed description taken in connection with the accompanying drawing, wherein:

Figure 1 is an edge view of a book arranged in accordance with the present i11- vention;

Fig. 2 is a plan view of one of the leaves;

Fig. 3 is a section taken approximately on line -3-3 of Fig. 2, on a greatly enlarged scale;

Fig. & is a View similar to Fig. 3 showing a modification; and

Fig. 5 is a view similar to Figs. 3 and showing a still further modification.

In accordance with my invention I make each leaf somewhat thicker at some point between the line of the inner ends of the slots or notches and the outer edge than it is in the vicinity at some point farther inwardly, preferably than at any point between the thickened part and the line of the inner ends of the slots or notches.

Thus, where a leaf, such as indicated at 1, is provided with one or more open notches or slots, 2, at the binding edge, that portion of the leaf between the binding edge and the line of the inner edges or ends of the notches or slots may be of gradually increasing thickness, as indicated at 3 in Fig. 3, the greatest thickness being at theeXtreme edge. When a stack of leaves is produced and placed in suitable clamping covers, 4, as indicated in Fig. 1, it will be seen that the marginal portion of the stack as a whole along the binding edge will be of gradually decreasing thickness from the extreme edge inwardly. If the metal clamping bars, 5 and 6, of the cover are made inclined on their inner faces, as indicated at 7 the inclination conforming te the decreasing thickness of th stack of leaves; the marginal portions of the stack of leaves will be held dovetailed in place when the clamping members are clamped down. Consequently the stack as a whole will be firmly locked, and each individual leaf which contains the novel characteristics described, will also be held in a dovetailed manner and cannot accidentally be withdrawn. Whenever a leaf is to be removed, the ins tening devices are simply loosened, and the leaf is withdrawn in the direction of the length of the slots or notches in its edge. When a leaf is to be placed into the book, the fastening devices are simply loosened, the leaf is slipped into the proper place with its notches receiving the usual posts, and the clamping bars are clamped down; the necessity of selecting a holding pin of the proper length and inserting it into the stack of leaves being entirely obviated. The discarding of the usual holding pins that pass through the round holes is quite an important factor because it has heretofore always been necessary to have on hand a variety of pins so as to make it possible always to have at hand a pin whose length corresponds to the thickness of the stack of leaves which are to be clamped together.

Instead of making the marginal edge of the sheet or leaf thicker than the entire body portion, the sheet may be thinned along a 'zone between the marginal bind- .ing edge and some point farther inward than the innermost line of the clamping bars. Such an arrangement is shown in Fig. 4 where the leaf is indicated at 8 while 9 is a zone containing the open-ended slots or notches, 2, and thinner at the middle than at the inner and outer edges. This arrangement permits the use of a leaf which does not have to be built up along one edge but is simply reduced in thickness to secure the proper wedge-like cross section. I

In Fig; 10 there is illustrated a leaf of uniform thickness except in the vicinity of the marginal edge where there is a thickened part or ridge, 11.

While I have illustrated and described with particularity only a single preferred form of my invention, including a few minor modifications, I do not desire to be limited to the exact details thus illustrated and described; but intend to cover all forms and arrangements which come within the terms employed in the definitions of my invention constituting the appended claims.

I claim:

1. A leaf for a loose-leaf book having slots opening out through the binding edge, said leaf having a part therein thicker than another part inwardly therefrom and containing the inner ends of the slots.

2. A leaf for a lose-leaf book having slots opening out through the binding edge, said leaf being thicker toward the outer ends of the slots than toward the inner ends.

3. A book comprising a clamping cover and a stack of leaves. arranged in said cover, Said cover having a clamping part overlying a clamping area'along one edge ofv said stack of leaves, said leaves being thicker outwardly toward the binding edge than along the inner edge of said clamping area.

4:. A book comprising a clamping cover and a stack of leaves arranged in said cover, said leaves being thicker. outwardly toward the binding edge than along the inner edge of a predetermined area extending along the binding edge, and said binding coverhaving clamping portions overlying the said clamping area and converging toward each other from their outer margins.

5. A leaf for a loose leaf book decreasing gradually in thickness from the edge which is adapted to be the binding edge of the leaf through anrarea extending inwardly a short-distance from said edge.

In testimony whereof I sign this specification.

GEORGE H. POTVVIN. 

